CVE-2026-129114
JSON::XS versions from 3.04 before 4.05 for Perl write one byte past a heap buffer when appending a one-byte chunk in incr_parse
Published Nov 14, 2026
CVSS n/a
EPSS n/a
KEV · Not listed
Description
JSON::XS versions from 3.04 before 4.05 for Perl write one byte past a heap buffer when appending a one-byte chunk in incr_parse.
The incremental buffer grows to one and a half times the length it must hold, with no room reserved for the terminating NUL. For an empty buffer and a one-byte chunk that request is one byte, which a buffer whose front was removed by earlier decodes can already have, so nothing is reallocated and the NUL lands one byte past the allocation.
A peer streaming data to an incr_parse consumer, choosing how the input is split into reads, can cause a one-byte heap out-of-bounds write.
The incremental buffer grows to one and a half times the length it must hold, with no room reserved for the terminating NUL. For an empty buffer and a one-byte chunk that request is one byte, which a buffer whose front was removed by earlier decodes can already have, so nothing is reallocated and the NUL lands one byte past the allocation.
A peer streaming data to an incr_parse consumer, choosing how the input is split into reads, can cause a one-byte heap out-of-bounds write.
Analysis
Affected Products
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CVE record
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NVD configurations
No data
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Red Hat packages
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OpenCVE enrichment
No data
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| unaffected |
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No data available yet.
Remediation
Vendor Solution
Upgrade to JSON-XS 4.05 or later.
Tracking
Advisories
Metrics
No CVSS v4.0
No CVSS v3.1
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
No EPSS score available.
Key SSVC decision points have not yet been added.
References
| Link | Providers |
|---|---|
| https://metacpan.org/release/MLEHMANN/JSON-XS-4.05/changes |
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History
Nov 14, 2026 12:00 PM
Description updated. Title updated. Weaknesses updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | JSON::XS versions from 3.04 before 4.05 for Perl write one byte past a heap buffer when appending a one-byte chunk in incr_parse. The incremental buffer grows to one and a half times the length it must hold, with no room reserved for the terminating NUL. For an empty buffer and a one-byte chunk that request is one byte, which a buffer whose front was removed by earlier decodes can already have, so nothing is reallocated and the NUL lands one byte past the allocation. A peer streaming data to an incr_parse consumer, choosing how the input is split into reads, can cause a one-byte heap out-of-bounds write. | |
| Title | JSON::XS versions from 3.04 before 4.05 for Perl write one byte past a heap buffer when appending a one-byte chunk in incr_parse | |
| Weaknesses | CWE-122 CWE-193 |
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| References |
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Subscriptions
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